Explosion circuit-breaker.



H. P. DAVIS & F. W. HARRIS.

EXPLOSION CIRCUIT BREAKER.

APPLICATION FILED NOV. so, 1908.

1,009,386. Patented N0v.21,1 911.

2 SHEETS-SHEET 1.

: jlggENTORS H. P.'DAVIS & F. W. HARRIS.

' EXPLOSION CIRCUIT BREAKER. APPILIOATION FILED NOV. so, 1908.

1,009,386, Patented NOV.21, 1911.

2 SHEETS-SHEET 2.

gL/J

V 1 is a longitudinal section of our interrupt.

' in Fig. 2.

UNITED STATES PATENT OFFICE.

HARRY P. DAVIS, OF PITTSBURGH, AND FORD W. HARRIS, OF WILKINSBUBG, PENN- SYLVANIA, ASSIGNORS, BY MESNE ASSIGNMENTS. TO WESTINGHOUSE ELECT-RIG &

MANUFACTURING COMPANY, OF EAST PITTSBURGH, PENNSYLVANIA, A CORPORA- TION OF PENNSYLVANIA.

EXPLOSION unborn-BR AKER.

Specification of'Letters Patent. I

Patented Nov. 21, 1911.

Application filed November 30, 1908. Serial No. 465,333.

have invented a new and usefullmprovemerit in Explosion Circuit-Breakers, of

which the following is a specification.

Our invention relates to interrupting devices for electrical circuits and particularly I to devices of this character which are employed in connection with circuits carrying i currents which are apt to have sudden and large increases in value,

The object of our invention is to provide a device which will instantaneously interrupt the circuit to which it is connected, in such a manner as to prevent the increase to the maximum value which it would attain if allbwed to exist for an appreciable interval.

Various forms and types of interrupting devices have been heretofore proposed and used, but all of them, so far as we are aware, have involved a time element of greater or less proportions and have, therefore, been incapable of interrupting circuits carrying large amounts of energy with sutficient promptnessto accomplish the results which we accomplish by means of our.

invention. 1

In the accompanying drawings, Figure ing device and Fig. 2 is a view. partially in section and partially in elevation of one ot the elements of the device shown in Fig. 1. Fig. 3 is a diagram of a system of distribution embodying two of the devices shown in Fig. 1. Fig. 1 is a sectional view of a modification of the device shown Referring now particularly to Figs. 1 and 2, the stationary contact terminal memher 1 comprises a plate 2 and a tubular block 3 which is screwed into a properly screw-threaded aperture in said plate and is provided with'a flaring opening 4 at its lower end. The other' stationary'contact terminal member 5 comprises a plate 6 i which is disposed parallel to, and above, the

plate 2, a block 7 of cup shape screwed into an aperture in the plate and having ascrewthreaded interior into which is screwed a block 8 having a laterally projecting flange or head 9 that rests upon the upper end of the block 7 when in operative position. A plate or washer 10 of mica, or other suitable insulating material, restsupon the upper surface of the head or flange 9 and is clamped between that surface and the adjacent surface of the flange or head 11 of a block 12,

the flanged portions 9 and 11 being clamped together by means of bolts 13. The-upper J end of the block 12 is provided with a supporting rodor bar 14 and the flange 11 is provided with a terminal piece 11. Lo-

cated below the terminal member 1 is a receptacle 15 which is filled, or partially filled, with sand or some other suitable granular material 16 and the upper end of which is in the form of a plate or flange- 17 which is parallel to the plates 2 and 6.

Located between the plates 2 and 6 and between the plates 2 and 17 and also above the plate 6 and below the plate 17, are sets of washers 18 and 19 which alternate with each other in position the former being preferably made of steel and the latter of mica. Extending through suitable openings in the plates 2, 6 and 17 and similar openings in the washers 18 and 19 are bolts 20 having insulating sleeves 21 and having nuts 22 at their lower ends whereby the contact terminal members and the box 15 may be clamped securely together and maintained in proper relation to each other. The plates 2 and v6 are respectively provided with terminal pieces 23 and 24; to which circuit wires may 'be attached. Normally located in the openings in the terminal blocks 3 and 7 so as to electrically, as well as mechanically, bridge the space between'the said blocks, is a tubular contact terminal 25 having the form of a projectile. The main portion 26 of the member threaded and seated inthe upper end of the I terminal piece 26. the space at the lower end of the shell 27 being filled by a disk or block 30. Located in the upper end of the shell 27'and having a recess to receive the upper end of the rod 29, is a block 31 of insulating material which is partially surrounded by a cap 32 of copper or other suitable conducting material which is thus insulated from rod 29, the space above the said cap and between it and the inner wall of the shell 27 being sealed by wax 33 or other suitable material. Resting upon the upper surface of the shell 32, is the lower end of a rod 34, the upper portion of which is surrounded by a coil-spring 35, the respective ends of which rest against a shoulder 36 .on the rod and the bottom of a recess in the head 12, this spring serving to normally hold the lower end of the rod 34 in contact with the shell 32.

In Fig. 3, to which reference will now be made, we have shown two of the devices illustrated in Fig. 1, the terminals 23 of these devices being connected in parallel through contact terminals 38 of switches 39 and in shunt to a high-resistance element 40. .The terminal pieces 11 are connected throughcontact terminals 41 of switches 39 to one terminal of a spark gap 42, the other terminal of said 'gap being connected to one terminal of the secondary of a series transformer 43 with which the main circuit is provided. One of the terminals of the gap 42 may be adjustable in order that the length of the gap between the terminals may be adjusted in accordance with the conditions under which it is desired that the explosive breaker should operate. Since the terminal 11 is connected to the cap 32, through the spring 35 and rod 34, and the cap is insulated from the rod 29, it is apparent that when the energy in the main circuit rises to such a value as .to jump across the gap 42, it will also jump from the cap 32 to the rod 29, thus producing a spark which will ignite the material 28 and thereby cause an explosion which will force the projectile 25 from its seat in the terminal blocks 3 and 7 into the sand 16 in the receptacle 15 thereby interrupting the circuit.

Instead of utilizing a jump spark to ignite the explosive material 28 we may employ any other means which may be found suit able and desirable, one such means being shown in Fig. 4, in which the various elements shown in Fig. 2 are reproduced. In this case, however, the cap 32 is connected to the rod 29 by a fusible wire or strip 44 which will serve to ignite the explosive material'28 when fused by a flow of energy which exceeds the safe limit for which the circuit breaker. is set.

The operation of the explosive breaker opens the shunt around the high-resistance .element 40 and thus makes the said resistcent terminals having alined tubular open-- ings, of a cartridge comprising a projectile normally seated in said tubular openings and a body of explosive material for forcing said projectile from its seats in said terminals.

2. The combination with a air of tubular contact terminals and a brldging contact member, of an explosive means for forcing the bridging member out of contact with said terminals, and a receptacle containing a body of granular materlal to receive the impact of said bridging member. v

3. A circuit breaker comprising a pair of tubular contact terminals, and a co6perating cylindrical member comprising a metal bridging portion, a shell operatively' disposed with reference to said bridging portion, a body of explosive material in the shell and sparking terminals in the explosive material.

4. In a circuit breaker, the combination with stationary tubular contact terminals, of a movable member comprising a projectile terminal located in and between said tubular terminals, a shell having an explosive charge behind said projectile terminal, sparking terminals for igniting said charge and means for arresting the movement of the projectile after it is ejected from the tubular terminals. 1

In testimony whereof, we have hereunto -subscribed our names this 18th day of N ovember, 1908.

- HARRY P. DAVIS. FORD W. HARRIS.

Witnesses CAROLINE E. SMYERS, BIRNEY' Hmns. 

